Power-line communication based surveillance system

ABSTRACT

A surveillance system configured for communicating with video cameras and other devices connected over a power-line communication network, such as within a residence, or alternatively a commercial building. The system may be manufactured and installed at low cost without the need to route individual cables to each surveillance video camera or device. Bandwidth within the power-line communication network is preferably dynamically allocated to device streams by a server in response to predetermined and event-driven priorities. By way of example, remote communication is supported for allowing remote access to surveillance data and control of the surveillance system. The system may be implemented as a standalone unit or integrated within existing forms of electronics equipment, such as consumer electronics equipment including a television set, a set-top box, or other forms of video-enabled equipment that is adapted for performing power-line network communication.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/624,706 filed on Jul. 21, 2003, now U.S. Pat. No. 7,450,638, issuedon Nov. 11, 2008, incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION

A portion of the material in this patent document is subject tocopyright protection under the copyright laws of the United States andof other countries. The owner of the copyright rights has no objectionto the facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the United States Patent andTrademark Office publicly available file or records, but otherwisereserves all copyright rights whatsoever. The copyright owner does nothereby waive any of its rights to have this patent document maintainedin secrecy, including without limitation its rights pursuant to 37C.F.R. §1.14.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains generally to surveillance systems, and moreparticularly to surveillance systems that communicate with surveillancedevices over a power-line network within the associated structure.

2. Description of Related Art

The use of area surveillance by surveillance systems has been on theincrease. In particular, residential surveillance systems are inparticularly high demand. Conventional systems, however, are difficultand expensive to install in existing structures, as installationrequires both the installation of a control center and video imagers(i.e., video cameras), along with the routing of cables interconnectingthe equipment.

Problems also arise with regard to connecting multiple video imagingdevices within current systems, in particular when utilizing analogvideo feeds which generally require a separate cable connection for eachvideo imager. Another set of issues surrounds the use of digitalnetworks, (i.e., Ethernet), wherein bandwidth limitation and costfactors arise. Although the cost of video imagers (i.e., charge-coupleddevice (CCD) imagers) has dropped below one hundred dollars per unit;the cost of control centers, monitors, and time lapse recording devicesare still generally beyond what many consumers, and some commercialinstitutions, can reasonably justify.

Therefore, a need exists for a surveillance system that is inexpensiveand can be deployed easily in residential and cost-sensitive commercialinstallations. The present invention satisfies those needs, as well asothers, and overcomes the deficiencies of previously developedsurveillance systems.

BRIEF SUMMARY OF THE INVENTION

This invention is a surveillance system utilizing a server that receivesvideo streams from video surveillance equipment and controls the displayof surveillance information to a user or sent to a video recordingdevice. Video streams are received by the server, over the ACpower-line, from video surveillance equipment that communicates usingpower-line communication (PLC). The server is configured for controllinghow the video streams are presented to a user or stored on a videorecording device. The system can support passing multiple surveillancestreams over the PLC network, wherein the server can allocate bandwidthfor the streams based on predetermined and event driven settings.

The surveillance system according to the invention is particularly wellsuited for use in the residential surveillance market. A user canreadily install a video camera anywhere a power outlet exists, becausecommunications are routed over the power lines within the residence (orcommercial building). The user need not route cabling to any of thevideo imagers or other devices to be connected within the system. Thepower connection and communication connection for each device (i.e.,video camera, display, etc.) are provided for by simply plugging thevideo camera into an AC power outlet.

The term “video” is utilized herein in its broadest sense, and maycomprise a video sequence with or without sound, low rate videosequences, sequenced image shots, along with other image forms receivedduring surveillance.

When multiple streams are passed over the AC power-line, the presentinvention can perform dynamic bandwidth allocation, wherein thebandwidth allocated for each video imaging device, or other device,connected to the AC power-line network is modulated in response topredetermined and event-driven settings. Bandwidth allocation isperformed by modulating bandwidth related configuration of the devicesconnected to the power-line network, such as video imaging devices. Byway of example, bandwidth related configuration of the video imagingdevice may comprise setting video controls such as color depth (i.e.,color/monochrome selection and number of bits per pixel), image size,image resolution, framing rate, and combinations thereof.

Allocation of bandwidth may follow predetermined bandwidth selections,such as in response to user prioritization of image feeds from videoimaging devices. Allocation may be driven by events, separately or incombination with user selection. By way of example, one form of eventthat can drive bandwidth allocation within the present system is that ofa motion detection event, preferably generated by a video imagingdevice, or in association with a location nearby the video imagingdevice. Dynamic bandwidth allocation, and other aspects of theinvention, allows the system to support the use of multiple videocameras within the bandwidth constraints of the power line, withoutresorting to the routing of high speed optical fiber connections orother similar high-bandwidth connections.

The present system utilizes a residential network server, such asintegrated within a consumer electronics device (i.e., television,set-top box, video recorder, or similar) as a control center unit andstorage device (i.e., hard-disk drive or other mass storage device) forthe surveillance system, eliminating the need to purchase expensive timelapse video recorders.

From a user perspective, it will be appreciated that with the presentinvention they need never again miss clear video images during anyemergency situation. By sending commands to the server the user cancontrol the video cameras communicating over the power-line network andthe presentation of the surveillance information. For example the usercan communicate commands to the server using a wireless remote control(i.e., infrared optical, or radio frequency), such as utilized forcontrolling their living room television set. Additionally, the systemcan provide remote monitoring over a remote communication medium, suchas telephone or Internet connectivity. No additional devices arerequired to implement the surveillance system, such as time lapseequipment, video recorders, controllers, image control consoles, and soforth.

The server for the present system may be hosted by a conventionalcomputer server, however, it should be appreciated that many otherdevices may contain suitable storage and processing hardware withinwhich programming according to the present invention may be executed forperforming the functions of the surveillance server described accordingto the present system. By way of example and not limitation, thesesystems include television sets, gaming consoles, set top boxes, videorecording systems, and so forth.

The present invention may be generally described as a system forproviding area surveillance, comprising: (a) at least one video imagingdevice configured for transmitting a video data stream over an ACpower-line; (b) a video display interface device; and (c) means forreceiving said video data stream from said AC power-line and controllingpresentation of said received video data stream as passed to said videodisplay interface device for storage or presentation to a user. A serverprovides the means for receiving the data stream and controllingpresentation, and when multiple surveillance video data streams areavailable it dynamically allocates the AC power-line bandwidth for thevideo imaging devices, such as by controlling their video framing rates,resolution, color mode, and so forth.

Preferably the video display interface is integrated within a computerserver, which preferably comprises a computer operating as a videoserver. The server can communicate video streams over the power line andis optionally configured for transmitting video data streams over aremote communication link to a location outside of the local PLC networkwhich is typically beyond the communication range of said AC power line.It will be appreciated that PLC network communication has a range thatis generally limited to a local area, such as within a residence. Theremote communication link allows communicating with remote devices overa form of wide-area network (i.e., telephone, cable, wireless telephonenetwork). The computer server operates according to selections made bythe user in response to interaction by a user interface which capturesuser commands for controlling the collection and display of the videostreams.

When communicating with remote devices outside of the power-lineinterface, the system preferably incorporates means of authenticating anauthorized user, such as the decrypting of communications with theremote electronic device in response to the entry of a properidentifier.

Video imagers for use within the present system can be generallydescribed as an apparatus for imaging an area under video surveillance,comprising: (a) an image sensor; (b) a communications interfaceconfigured for communicating over an AC power-line with a server,wherein dynamic bandwidth allocations are received from the server, andvideo signals from the image sensor subject to the dynamic bandwidthallocation are transmitted to the server. Preferably the video imagerencodes the video signals into a format according to a Moving PictureExperts Group (MPEG) video format. In addition, the video imagerpreferably senses motion and communicates that motion over the ACpower-line to the computer server.

Computer servers for serving the video within the present invention maybe generally described as an apparatus for controlling videosurveillance, comprising: (a) a power-line interface configured forcommunicating over an AC power-line with remote video imaging devices;(b) a user interface configured for capturing user preferences forcontrolling the collection and display of the video streams; and (c) acomputer server configured for allocating bandwidth to remote videoimaging devices and receiving video streams subject to the bandwidthallocation over the power-line interface, wherein the computer server isalso configured to communicate these video streams for storage and/ordisplay device according to user preferences.

The computer server preferably also comprises a data storage devicewithin which selected portions of video streams may be stored, and aremote communications interface configured for communicating the videostreams received within the computer server to a remote user at alocation beyond the range or extent of the power-line interface.

The surveillance system according to the present invention may beimplemented as programming for execution on a computer which has thenecessary PLC network interface, processing power, communication, andstorage hardware to execute the server functionality. The programmingmay be resident within programmed circuits, computer readable media(i.e., physical media or content distributed such as by downloading), orcombinations thereof, without departing from the teachings herein.

By way of further illustration the invention may be generally describedas a method of providing area surveillance, comprising: (a) generatingvideo signals in response to video surveillance of one or more areas;(b) communicating the video signals over an AC power line subject todynamic bandwidth allocation; (c) receiving the video signals within acomputer server connected to the AC power line; and (d) communicatingselected portions of the video signals from the computer server to adisplay in response to predetermined or event driven criterion. Themethod preferably also includes storing select elements of the videosignals and altering bandwidth allocation for video signals in responseto predetermined or event driven criterion, such as the detection ofmotion.

A number of aspects of the present invention are described herein, itshould be appreciated that these aspects may be implemented separatelyor in various combinations thereof, without departing from the teachingsof the present invention.

An aspect of the invention is that of providing a surveillance systemthat may be installed within a building structure without routingcommunication wiring between stations.

Another aspect of the invention is that of providing a surveillancesystem that may be manufactured at low cost.

Another aspect of the invention is that of providing a surveillancesystem whose functionality may be integrated into existing consumerelectronic equipment at low incremental cost.

Another aspect of the invention is that of providing a surveillancesystem that can operate in conjunction with other networked devices,such as television sets, personal computers, audio systems, and thelike.

Another aspect of the invention is that of providing a surveillancesystem that can automatically configure itself for the conditions.

Another aspect of the invention is that of providing a surveillancesystem that supports remote monitoring and recording capabilities.

Another aspect of the invention is the routing of video streaming fromsurveillance video cameras and other devices over the power lines in aresidential or commercial structure, to a server that controlssurveillance activity.

Another aspect of the invention is reducing bandwidth requirements pervideo camera utilizing dynamic bandwidth allocation mechanisms based onprioritization that may be based on motion sensing.

Another aspect of the invention is providing a surveillance networkconfiguration that allows various surveillance equipment, as well assensors, annunciators and displays to be connected.

Another aspect of the invention is provide a surveillance system inwhich the resolution, color range (i.e., monochrome or amounts of dataper pixel), and framing rate of the captured image stream communicatedover the surveillance network may be adjusted to suit conditions.

Another aspect of the invention is a surveillance system in which videocameras communicate video encoded in a format according to the MovingPictures Expert Group (MPEG).

Another aspect of the invention is to provide a surveillance system thatis controlled by a set-top box, television, or other form of consumervideo equipment within which surveillance features have been integrated.

Another aspect of the invention is to provide a surveillance system inwhich the control data may be communicated to each video camera forcontrolling video camera settings and optionally pan and zoom.

Another aspect of the invention is to provide a surveillance networkthat may securely communicate selected data to a remote location or becontrolled from a remote location securely, such as over an Internetconnection.

Another aspect of the invention is to provide a surveillance network inwhich devices request bandwidth from a server which allocates an amountof bandwidth depending on priorities and activity.

A still further aspect of the invention is to provide for controlling asurveillance system using a standard video remote control device, suchas when watching a television set.

Further aspects of the invention will be brought out in the followingportions of the specification, wherein the detailed description is forthe purpose of fully disclosing preferred embodiments of the inventionwithout placing limitations thereon.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

The invention will be more fully understood by reference to thefollowing drawings which are for illustrative purposes only:

FIG. 1 is a block diagram of a surveillance system according to anembodiment of the present invention, shown with a server communicatingwith multiple video cameras over a power-line network.

FIG. 2 is a block diagram of a video camera configured for operationwithin the surveillance system according to an aspect of the presentinvention, and shown with optional motion sensing circuitry.

FIG. 3 is a block diagram of a server configured for communicating withand controlling the operation of video cameras and other devicesaccording to an aspect of the present invention, and shown configuredfor integration within a television set or set-top box.

DETAILED DESCRIPTION OF THE INVENTION

Referring more specifically to the drawings, for illustrative purposesthe present invention is embodied in the apparatus generally shown inFIG. 1 through FIG. 3. It will be appreciated that the apparatus mayvary as to configuration and as to details of the parts, and that themethod may vary as to the specific steps and sequence, without departingfrom the basic concepts as disclosed herein.

1. System Descriptions

1.1 Surveillance System

FIG. 1 illustrates an example of the system shown deployed within aresidential structure 10, having power lines 12 routed to multipleoutlets, such as represented by outlet 14, in the different rooms andlevels within the structure. The system is configured with a server 16that operates as a control center for the surveillance system and whichpreferably supports a communication link 18 extending from the structureto an external network, such as a cable modem, xDSL telephone modemconnection, or similar link over which data may be remotelycommunicated, such as over the Internet.

Power lines 12 are utilized as a power-line communication (PLC) network12 within a residence (or business) for allowing server 16 tocommunicate with various remote devices. By way of example, a few videocameras 20, 22, 24 are depicted which are configured for transmitting avideo stream to server 16 over power-line network 12. It should beappreciated that different forms of clients may be attached to server 16over power-line network 12, such as video clients (displays), videocamera clients, audio clients, sensor clients, and numerous other formsof devices. Video cameras may send audio and/or video streams to server16, while server 16 is configured to send control commands but notstreams to the video cameras.

1.2 Video Cameras

FIG. 2 illustrates an example of a video camera 20 configured accordingto the present invention for communicating with server 16 over thepower-line network. An analog video signal from CCD Imager 26 is sent tosignal processor 28, which for example may comprise analog signalconditioning, along with analog-to-digital conversion, and optionallydigital post processing, prior to receipt by an encoder 30. The inputsignal is then encoded by encoder 30 in combination with memory 32 andconverted into a digitally formatted stream, such as according to MotionPicture Experts Group (MPEG) standards for video streams, as exemplifiedherein. PLC interface 34 receives the formatted (i.e., MPEG) videostream, which may be optionally encrypted within encryption module 36,prior to communication of the video feed to server 16 through an ACpower plug 38 and the power-line network 12 of FIG. 1. It is preferablethat PLC interface 34 encrypts communications over power-line network 12to prevent information access by unauthorized parties, such as may ariseif a competitor or adversary were to tap into the PLC network. It shouldbe readily appreciated that a number of users, such as neighboringhomeowners, may share the same distribution transformer wherein PLCnetwork signals being communicating by one user, such as in a firsthome, are available to additional users, such as in a second, third,fourth, fifth home and so forth.

A control processor 40 for the video camera, such as a centralprocessing unit (CPU), microprocessor (MPU), or high density logiccircuitry, is preferably connected through an internal bus 42 to otherfunctional blocks. Control processor 40 can access memory 44 withinwhich is stored programming for executing the control program, andgenerally data entries, stack space, scratchpad memory, andconfiguration variables. Commands for video camera 20 are receivedthrough PLC interface 34 and communicated to control processor 40, whichcan likewise communicate status and other information, as well asproviding video signal feed, back to server 16.

In response to commands from control processor 40, encoder 30 canpreferably adjust at least the resolution and frame rate of the encodedpictures being returned to server 16. These adjustments allow fulfillingdynamic bandwidth allocations determined by the server, such as inresponse to predetermined or event-driven settings. An as example ofbandwidth control, consider an example wherein control processor 40receives a high-resolution command from server 16 which controls encoder30 to change the output resolution to 720×480 from 360×240 pixels. Byway of further example, in the case of a low-rate command, encoder 30may change the frame rate from 30 frames/second to 5 frames/second.Other aspects of the video transmission may also be controlled byencoder 30 to fulfill a desired dynamic bandwidth allocation, such asthe selection of a color mode or a monochrome mode which reduces videobandwidth. Furthermore, encoder 30 may optionally perform featureenhancement, light optimization, and so forth to enhance the video fromthe imager and/or to extract additional information from the imagestream. In the embodiment described, the encoding parameters arepreferably sent based on the MPEG standard, allowing automatic decodingof mode selection for the received video within server 16.

A motion sensor 46 is also shown connected to control processor 40 whichdetects motion typically in the field of view of imager 26. Othersensors may be utilized additionally, or as an alternative, to motionsensor 46, such as infrared sensors, pyroelectric detectors, audiodetectors, and so forth. Motion sensor 46 sends a signal to controlprocessor 40 in response to detected motion, which communicates thecondition to server 16. Server 16 may respond to the detection of motionby changing the prioritization of the video camera input and/orassigning a larger bandwidth to the video camera input.

It should be appreciated that other methods may be relied upon forsensing motion. By way of example, if encoder 30 is implemented forencoding video in an MPEG format, it will extract motion vectors foreach video block as part of the encoding process. When no motion existsin the frame, all the motion vectors are zero. Encoder 30 may be adaptedto transmit a signal to control processor 40 in response to motionvectors crossing a given threshold value. This motion threshold valuebeing set sufficiently high so as not to be exceeded by activation ordeactivation of lighting, the flight of insects and moths in the fieldof view, and other common non-threatening motion scenarios.

Another solution for motion detection is to utilize a high-pass filtered(i.e., differential) video signal which is converted to digital insignal processor 28, with a result being added up and a total valueobtained at each frame. The value is monitored, and in response tofluctuations beyond a predetermined, or computed threshold value, signalprocessor 28 sends a signal informing control processor 40 of thedetected motion. As an alternative to determining a total value, themaximum value in a frame may be employed for motion sensing. These fewexamples being provided by way of illustration, wherein it should beappreciated that motion may be detected in a number of alternative waysknown to one of ordinary skill in the art.

1.3 Server

FIG. 3 illustrates by way of example the functionality within server 16.A video stream or data is received from AC power plug 50 to PLCinterface 52 which decodes the power-line transmissions and decryptsreceived data or encrypts outgoing data through encryption-decryptionmodule 54. PLC interface 52 communicates information across bus 56 to acentral processor 58 and/or in some cases other functional blocksconnected to bus 56. The available bandwidth within the PLC network isdynamically allocated by central processor 58 which controls its own useof bandwidth and the bandwidth utilized by video imaging devices andother devices connected on the PLC network. Central processor 58operates in combination with memory 60 to typically control all theblocks connected to bus 56. Programming, temporary data storage,operating data and parameters, and so forth are stored in memory 60 foruse by central processor 58.

By way of example the video data stream received by PLC interface 52 mayarrive from video camera 20, 22, 24 as shown in FIG. 1, or from othervideo cameras or devices connected on power-line network 12. Videostreams are passed to a decoder 62 which decodes the digital videoformatting in combination with memory 64 into an appropriate format foroutput, such as on a display and audio system. The input format todecoder 62 preferably follows an MPEG standard, although other videoprotocols may be utilized. Decoding is exemplified herein for providinganalog outputs as the decoder drives digital-to-analog converters 66,68, into a display device 70 and an audio device 72, comprising anamplifier 74 and an audio annunciator 76, such as a speaker or system ofspeakers. If the video, or portions thereof, are to be recorded withinthe system, the video stream from PLC interface 52 is also communicatedto a data storage device 78, exemplified as a storage interface 80controlling a hard-disk drive 82, or other form of fixed or removablestorage media, and/or a form of solid state memory.

The system of the invention may be controlled by the user in a number ofways, for example a set of user inputs 84 is shown connecting through aninterface 86. User input 84 may comprise a simple keypad, a keyboard, apointing device, or any other convenient user interface supported byserver 16. Additionally, a wireless communication port 88 is preferablysupported which by way of example can receive commands from an infraredremote control device 90, such as for controlling a television set orvideo recorder.

Modem 92, or other remote network communication interface, is configuredfor communicating from the server to the environment beyond thepower-line network, such as through the Internet. Modem 92 allows thesystem to operate in a larger context, for example as a server providingremote access to authorized parties, or as a client of externalservices. Remote access allows a person, such as a homeowner, to beremotely alerted to conditions at their residence, to control aspects ofthe system, and to view or otherwise monitor household activity, such asvideo streams generated by the surveillance video cameras. Whenoperating as a client, services may be utilized from a network, such asthe Internet, for example extracting data from database services,communicating with security personnel at a central station, downloadingnew system and device drivers or parametric data, and so forth.

It should be appreciated that the surveillance system of the presentinvention may be integrated within consumer electronic devices whichhave been configured with the requisite communication, decoding,storage, and display capabilities. As an example, an embodiment as sofar described above may be considered to be integrated within atelevision set, or set-top box, having Internet connectivity and apower-line interface as described.

A tuner front-end 94 may be coupled to or within server 16 for providingtelevision reception, and playback from video and/or audio systemshaving RF output. Tuner front-end 94 receives an RF signal from anantenna, satellite down-converter, or a cable network passing it todecoder 62, which in combination with memory 64, decodes the demodulatedsignal for display. It should be appreciated that television styleprogramming may be received from the reception of broadcast televisedprogramming, as well as cable based or satellite based televisionprogramming. The system may also record the video stream, whereindecoder 62 sends the stream to data storage device 78 through bus 56. Toreplay the video stream, decoder 62 in combination with memory 64,receives the video stream from data storage device 78, and/or the streammay be communicated over modem 92, or over the power-line network 12 toexternal displays and/or audio or video equipment.

The incorporation of the surveillance system within a television orset-top box unit, or similar, can provide a nexus of benefits. By way ofexample, a user watching the television, or a television connected tothe system, can be alerted on-screen when motion is sensed by one of thevideo cameras. For instance, a small window may be opened on the videoscreen in response to detected motion upon which the video stream isdisplayed from the associated video camera. The user may then elect howthey want to deal with the situation, and may zoom the video camerastream window up to full-size and view other video camera streams, andcontrol other operations under the direction of the surveillance system,or even connect through the modem to external networks such as telephoneor the Internet, such as summoning help.

Alternatively, one or more overlapped small screens may be displayedcontinuously in a portion of the screen showing selected video feedswhile the user watches television or other programming on the remainderof the screen. These small screens can be selected to zoom them to fullsize, when appropriate. It should be appreciated that a number ofadditional features are inherent in combining the surveillance system ofthe present invention with other consumer electronic devices, as will beobvious to one skilled in the art. Integrating functionality in thismanner provides a number of benefits as outlined above.

1.4 Bandwidth Control

Server 16 manages bandwidth utilization within PLC network 12. Towardoptimizing utilization of bandwidth, the devices connected to the serverover PLC network 12 send a request for bandwidth assignment prior tosending a data stream. Central processor 58 within server 16 receivesbandwidth requests from devices on the PLC network while having its ownset of transmission requests for sending data out to devices connectedon the PLC network, such as displays, annunciators, and so forth.Allocation is determined in response to these requests by centralprocessor 58 within server 16 toward optimizing bandwidth use based onpriority and size considerations.

Consider the example of two bandwidth requests, for streams X and streamY. Although stream X may be of slightly higher priority than stream Y,the relative priority of communicating stream X in color (as opposed tomonochrome) is probably less than the importance of communicating streamY in monochrome. The allocation routines, therefore, preferably takeinto account the incremental priorities of the request, wherein anaction may be defined by a number of priorities, allowing tradeoffs tobe made readily between priority and bandwidth. Additionally, theassociated data sizes of a data transfer may be taken into account whenappropriate. By way of example, consider a request for transmitting ablock of control information to a device. The control information may beof lower priority than a given stream, but since the control informationmay include only about one hundred bytes while the stream is continuoususing about over a hundred thousand bytes per second, it is probablymore important to pass the few control bytes while dropping streambandwidth (at least for a short time), or delaying transmission, ortaking other bandwidth reducing measures. One preferred method ofhandling short blocks of control data considering their generally smallsize is to automatically allocate bandwidth for them at higher prioritythan any streams, wherein the allocation routine is not bogged down withworking out priorities on small data blocks.

Consider an example of bandwidth control, wherein it is assumed that thetotal bandwidth of the PLC network 12 is eight megabits per second (8Mbps) according to a payload rate, while server 16 sends a five megabitsper second (5.0 Mbps) video stream to a data storage media on a client,such as for a timer recording (not shown). In this scenario the highestpriority (i.e., priority=1) may be given to the timer-recording stream,with inputs from video camera 20, 22, 24 being at a lower priority(i.e., priority=2) and held to sending video streams at a one megabitsper second (1.0 Mbps) rate from each video camera (i.e., priority levelof two). This situation is listed in Table 1.

Consider that video camera 24 then detects a motion, wherein itcommunicates the detected motion to 16, which raises the priority ofvideo camera 24 (i.e., priority changes from 2 to 1), while lowering thepriority of the timer-recording stream (i.e., priority changed from 1 to2), and dropping the priority of video cameras 20, 22 down to even alower priority (i.e., priority=3). This example situation of bandwidthreallocation is listed in Table 2.

Bandwidth allocation may occur with server 16 sending a command to videocamera 24 requesting a video stream rate of four megabits per second(4.0 Mbps) from the current one megabit per second. In response videocamera 24 raises video resolution and/or frame rate. If the newbandwidth supplied does not support the higher resolution or higherframe rate, the video camera may for example raise only the picturequality, allowing the user to view captured motion at a higher quality.

In response to cessation of detected motion by video camera 24, it maysend a signal to server 16 requesting the bandwidth be returned to theoriginal data rate, wherein video camera 24 would alter pictureresolution, frame rate and picture quality to the original setting whencommanded to do so by server 16. By way of example and not oflimitation, bandwidth for each device may be set to default values aslisted in Table 1.

Utilizing this bandwidth control mechanism, or a similar scheme, thelimited network bandwidth is efficiently utilized allowing more devices,such as video imagers (video cameras), to be installed on the givennetwork. In addition bandwidth allocation provides a means forregulating the rate at which recording space, such as in a hard diskdrive, is being consumed. It should be appreciated that video imagersadapted for operation within the present system, may be configured tocommunicate a video stream only in response to detecting a valid triggercondition, such as the detection of motion, for example when someoneapproaches and/or attempts to break into an area under surveillance.This approach eliminates the collection and display of video streams ofstatic image conditions, such as empty rooms and entryways, and reducesstorage requirements. Alternatively, the system may buffer video streamsfor some period of time, without displaying them to a user. If the videocamera is then triggered by sufficient detected motion, the priorsegment of video is available and may be stored with the video that wascollected after the motion trigger.

1.5 Remote Monitoring

A beneficial optional feature of the present surveillance system is thatof providing remote monitoring by the surveillance system, such asutilizing a modem to communicate to a remote location over the Internet.In this way an authorized user can access surveillance data, such asviewing surveillance video from each video camera, and control theoperations and configuration of the surveillance system. For example, inresponse to detecting motion by one of the video cameras, the server caninitiate a communication to one or more authorized users over atelephone number, such as a cellular phone number. The user may viewvideo over the small video screen of the phone to monitor the situation.The user may elect to then call a neighbor, a security company, or thesheriff's department. The system can be configured to allow the user tocommunicate commands for controlling the system using key entry, voicecommands, menu navigation and so forth.

According to one optional aspect of the system the user can select tohave input from a microphone, such as the microphone on a cellularphone, to be directed for output from one or more audio annunciators atthe area under surveillance. This ability can provide concrete evidenceto a suspected intruder that they are being watched, whereupon they aremore likely to take their leave.

By way of example, the system may be configured to generate an alert tothe user when someone approaches a secured area, such as the front door,which may be optionally qualified by registering a doorbell activationor door knocking. Upon being triggered in this manner, the system ispreferably configured to allow the user to interact with the party atthe door, if they so desire. The system in this mode can operate as aform of intercom for communicating with persons remotely.

The remote communication can be utilized for allowing a remote securitycompany to monitor activity from the surveillance system and to takeappropriate actions. For example, the security company may view and/orrecord the incoming video stream, such as to a hard disk drive, whereinsecurity personnel are alerted and some evidence made available, despitesubsequent disconnection or damage to the surveillance system by anintruder.

The communication with remote services by the server is preferablyencrypted, wherein a password or other suitable authorization token(i.e., PIN, bio-metric data about user, and so forth) is required todecrypt the information. The remote capabilities allow a user that is atwork or on vacation to rest secure in the knowledge that their residenceis being monitored and that they will be notified in the event that apossible problem is detected, whereupon they may take correctiveactions.

2. Optional Aspects

It should be appreciated that devices connected to the PLC networkaccording to the invention may be electronically commanded by the serverto execute any desired additional functionality. By way of example andnot of limitation, zooming, tilting or panning capabilities of the videocamera in addition to the control of video modes and encoding asdescribed above. The user may modulate the video camera angle(positioning and zooming) with a remote control, or utilizing a remotecommunication device, such as a phone, PDA, or computer system, to seewhatever is of interest.

Remote content storage may be provided for the system, wherein contentis communicated to a remote data storage unit, preferably located in ahidden location within the same building, such as a hard disk drivesubsystem installed within the attic of a house and communicating over awired, or more preferably a wireless connection, with the server. Videodata may be buffered within the remote content storage system, whereinvideo and other data may be saved that precedes a trigger event, such asmotion, but is otherwise discarded. The surveillance information(evidence) is therefore kept secure from intruders.

It should be appreciated that wireless communication networks or otherforms of network connectivity may be less preferably utilized, insteadof the PLC network, without departing from the teachings of the presentinvention. It should be appreciated that the PLC network may be utilizedin combination with wireless networking or other forms of networking toprovide adequate coverage for the site. By way of example, a remotesolar-powered video camera may be connected to the surveillance systemover a wireless link connecting into the server or connected into thePLC network.

The system can be configured to scroll through video camera images on aperiodic basis, wherein the image from each video camera is shown for agiven length of time on a cyclical basis. This is equivalent to an equalprioritization of inputs.

The system can be configured for prioritization of video camera channelsbased on a predetermined or programmatic hierarchy. Certain video camerainputs may be intrinsically of greater value, such as at an entry way,wherein they may be given a higher priority and displayed more often orfor greater lengths of time. Furthermore, remote signals or imageinformation may be utilized to modulate the prioritization hierarchy,for example motion sensing trigger increasing the priority of anassociated video camera.

The system is optionally configured for accepting input from additionaldevices coupled to the system, such as audio or video streaming.Although these sources require significant bandwidth, still framing maybe utilized at periodic intervals until trigger conditions, such asmotion, are detected. Other non-video sensors may be coupled to thesystem, such as sensors for smoke, temperature, water, impact, window ordoor motion, foot traffic, and so forth. It should be appreciated thatthese forms of sensors require only a small amount of bandwidth. Outputfrom these sensors can be configured to trigger prioritization changesof system inputs, such as video cameras located in the vicinity of thesensor, or even changing orientation on video cameras located in thevicinity to point toward the detected event. Separate sensors may becoupled to the system, or they may be integrated with the video camera.

Similarly, the system is optionally configured for conveying informationto additional output devices. The system can direct information to othermonitors connected over a residential network (wired or wireless) orremote access device connected over the Internet, or other network.Aside from these Internet type connections, the power-line networkwithin the residence may be utilized by the system for conveying outputinformation to emergency annunciators and control devices, such asalarms, light flashers, strobes, electronic door locks, fans, lightcontrol modules, pumps, and so forth.

The present invention has been described according to a preferredembodiment having optional features. It should be appreciated that theinvention may be implemented with or without these features orvariations thereof without departing from the teachings of the presentinvention. Aspects of the invention may be practiced in combination, orin some cases separate from the overall surveillance system, withoutdeparting from the teachings of the invention.

Although the description above contains many details, these should notbe construed as limiting the scope of the invention but as merelyproviding illustrations of some of the presently preferred embodimentsof this invention. Therefore, it will be appreciated that the scope ofthe present invention fully encompasses other embodiments which maybecome obvious to those skilled in the art, and that the scope of thepresent invention is accordingly to be limited by nothing other than theappended claims, in which reference to an element in the singular is notintended to mean “one and only one” unless explicitly so stated, butrather “one or more.” All structural and functional equivalents to theelements of the above-described preferred embodiment that are known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the present claims.Moreover, it is not necessary for a device or method to address each andevery problem sought to be solved by the present invention, for it to beencompassed by the present claims. Furthermore, no element, component,or method step in the present disclosure is intended to be dedicated tothe public regardless of whether the element, component, or method stepis explicitly recited in the claims. No claim element herein is to beconstrued under the provisions of 35 U.S.C. 112, sixth paragraph, unlessthe element is expressly recited using the phrase “means for.”

TABLE 1 Default Bandwidth Settings within 8 Mbps PLC Channel PriorityChannel Bandwidth 1 Timer Rec 5.0 Mbps 2 Camera 20 1.0 Mbps 2 Camera 221.0 Mbps 2 Camera 24 1.0 Mbps

TABLE 2 Bandwidth Reallocation in Response to Motion Priority ChannelBandwidth 1 Camera 20 4.0 Mbps 2 Timer Rec 2.0 Mbps 3 Camera 22 1.0 Mbps3 Camera 24 1.0 Mbps

What is claimed is:
 1. An apparatus for providing area surveillance,comprising: a video imaging device configured for capturing video imagesand transmitting a video data stream over an AC power-line; and anencoder, within said video imaging device, configured for dynamicallychanging the bandwidth of said video data stream as output by said videoimaging device over said AC power-line, wherein bandwidth can beremotely adjusted in response to selection of any of multiple modeswhich dynamically change the bandwidth of said video data streamtransmitted over said AC power-line; wherein said video imaging deviceis configured for transmitting said video data stream to a video displayinterface device configured for controlling presentation by remotelyadjusting bandwidth of said video data stream as passed to the videodisplay interface device for storage or presentation to a user.
 2. Anapparatus as recited in claim 1, wherein said dynamically allocatedbandwidth is responsive to the bandwidth needs of additional videoimaging devices, or other devices, communicating over said AC power lineas controlled by the video display interface.
 3. An apparatus as recitedin claim 1, wherein said dynamic allocation of bandwidth is performed inresponse to predetermined and event-driven settings.
 4. An apparatus asrecited in claim 1, wherein said dynamic allocation of bandwidthmodulates the amount of bandwidth allocated to said video imaging devicein response to a detected motion event.
 5. An apparatus as recited inclaim 1, wherein said modes of said video imaging device comprise atleast one video characteristic selected from the group consistingessentially of color depth, image size, image resolution, and framingrate.
 6. An apparatus as recited in claim 1, further comprising acomputer server coupled for communication over said AC power line andconfigured as a video display interface.
 7. An apparatus as recited inclaim 6, wherein said computer server comprises: a computer operating asa video server configured for communicating video data streams within aselectable bandwidth allocation over said AC power line with at leastone said video imaging device; and a remote communication link withinsaid computer server which is configured for communicating video signalsreceived from at least one said video imaging device to a locationbeyond the communication range of said AC power line.
 8. An apparatus asrecited in claim 6, further comprising a user interface configured forcapturing user commands for controlling the collection and display ofsaid video streams.
 9. An apparatus for providing area surveillance,comprising: a video display interface device configured for receiving avideo data stream from one or more video imaging devices over an ACpower-line and controlling presentation of the received video datastream as passed to said video display interface device for storage orpresentation to a user; a computer and memory coupled to said computerwithin said video display interface device; and programming executableon said computer as read from said memory for, dynamically controllingthe allocation of bandwidth in response to remotely adjusting at leastone mode having multiple settings within one or more video imagingdevices configured for transmitting said video data stream over said ACpower line to said video display interface device.
 10. An apparatus asrecited in claim 9, wherein said dynamically allocated bandwidth isresponsive to the bandwidth needs of said one or more video imagingdevices communicating over said AC power line.
 11. An apparatus asrecited in claim 9, wherein said dynamic allocation of bandwidth isperformed in response to predetermined and event-driven settings.
 12. Anapparatus as recited in claim 9, wherein said dynamic allocation ofbandwidth modulates the amount of bandwidth allocated to said one ormore video imaging devices in response to a detected motion event. 13.An apparatus as recited in claim 9, wherein said at least one mode ofsaid one or more video imaging devices comprises at least one videocontrol parameter selected from the group consisting essentially ofcolor depth, image size, image resolution, and framing rate.
 14. Anapparatus as recited in claim 9, further comprising a mass-storagedevice coupled to said computer and configured for storing said videodata streams received from said at least one video imaging device. 15.An apparatus as recited in claim 9, wherein said video display interfacecomprises a computer server.
 16. An apparatus as recited in claim 9,further comprising a remote communication link within said video displayinterface device, said remote communication link configured forcommunicating video signals received from said one or more video imagingdevices to a location beyond the communication range of said AC powerline.
 17. An apparatus as recited in claim 16, wherein said remotecommunications link is configured for authenticating a usercommunicating through said remote communications link.
 18. An apparatusas recited in claim 9, further comprising a user interface configuredfor capturing user commands for controlling the collection and displayof said video streams from said one or more video imaging devices. 19.An apparatus as recited in claim 9, wherein said video display interfacedevice is integrated within a set-top box, television, or videorecording device.